Ducted fan aircraft



FIG. 1 is a perspective view of a ducted fan aircraft showing my new design;

FIG. 2 is a plan view thereof;

FIG. 3 is a side view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a front elevational view thereof; and

FIG. 6 is a rear elevational view. 

The ornamental design for a ducted fan aircraft, as shown and described. 